more speed ( essentially a little underexposure ) doesn't mean more grain. how did you come to that conclusion? phenidone is known as a developing agent that can give an extra stop. since you were making a diafine type developer, i thought it was one of the characteristics you were emulating. another one of the great properties of diafine is the keeping properties of bath A ( well over a year ). when you say the keeping properties are good, is it because you've stored a control bottle that you've tested, say, 6 months down the road? i suspect that 65g sodium sulfite is contributing substantially to the fine grain plus the shortish time of 3 + 3 and the borax.
sincerely, good luck with your experimenting. i really hope this ascorbate developer proves to be as stable as diafine. looking forward to your future reports on this developer.
keeping properties of bath A (or any other developer) depended from a) pH b) amount of Sodium sulfite or other antioxidant (by example hydroxylamine in some color dev). in true-two-bath developers bath A have low pH (~6.5-7) and developing can't start in bath A. low pH increase storage life of bath A. sodium ascorbate also working as slow antioxidant and with 65g/l of sodium sulfite extend life of solution. my experience tell me that developer solution with slightly acidic pH have very good keeping properties.
other interesting formula which work like modified Diafine is metol-ascorbate 2bath developer MCDD:
Sodium sulfite 60g
Sodium Ascorbate 10g
Sodium metabisulfite 5g
Sodium sulfite 35g
3min in each bath. give same density as PC-Diafine. but grain/sharpness/contrast is slightly more
I wonder if this formula works without ascorbate ... I think it does.
Originally Posted by Relayer
Without ascorbate it resembles one of many DD23 or DD76.
if you omit ascorbate this formula can't be working because acidic pH in bath A (5g/l sodium metabisulfite). many 2bath variation of D23/D76 really isn't true-two-bath developers because developing started in bath A. it's really lazy-split. by example you can put film in any stock (D76,D23,XTOL or other) for 30% less time than required and after this put film into alkali (borax, soda etc) for 3-5min. this is well-known method described in many books
Originally Posted by eSPhotos
in case of true-2bath developing can't start in bath A! you can put film in bath A for 3min ... or 15min without any differences in result
I have done some testing of Diafine-C with APX 100 film.
At 3 min +3min the negatives are thin, at 5min +5min ,slightly too dense and the EI greater than box speed.
Developing in 20 ml part A +500ml part B for 5min to simulate the effect of carry-over on the film surface, tank and reel gives a faint image apparently insignificant compared to 5min + 5min 2 bath development.
My conclusion is that Diafine-C is a true 2-bath developer, the first succesful one to be disclosed of the phenidone/ascorbate type.
Last edited by Alan Johnson; 07-01-2011 at 02:41 PM. Click to view previous post history.
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Alan, thank you for testing! really don't need to put film in bath A more than 3min. bath B very depended from agitation. I recommended 5 initial rotation and 2-3 rotation per min
Just an FYI
Every 2 bath developer I tested showed some development in bath A alone.
Some gave slight developement and in some 2 bath formulas MOST of the development happened in bath A.
Daifine is one that only gives a very faint image in bath A if left in for only 3 minutes.
Try stand devlopment for and hour in Daifine bath A alone and you will get printable negatives.
Try it. Shoot off a sequence of 3 brackted shots, clip those off the end of your roll and toss them in bath A alone and wait.
catechol in sodium metabisulphite as a bath A won't develop until the film is immersed in sodium hydroxide as a bath B will do all the development.
This is very interesting. I was going to try a 2-part phenidone/C developer myself with the main difference being no sulfite (I have had great success with PC sulfite-free developers). The recipe I had in my notes to try is as follows:
Ascorbic Acid - 6g
Phenidone - 0.15g
Sodium Bicarbonate - 3g
Water to make 1L
Borax - 20g
Water to make 1L
I use the same amounts of Phenidone/Vit-C/Borax in a L of water to make a 1-part developer that works well and lasts a very long time (bottle over 6 months old works like new). I have no idea how/if this version works but I will report back when I find out.
Michael, did you get around to trying this? Did it work?
Originally Posted by MichaelMadio